Types of Dental X-Rays

CC Image by Dr. Alan Carr

CC Image by Dr. Alan Carr

During many dental appointments, dental x-rays are taken. Do you know what the reason is, or the difference between different types of radiographs? Take a look at this guide to dental x-rays, then be sure to ask your dentist if you have any further questions.

Bitewing X-rays

Once or twice per year, many dentists like to take bitewing x-rays. These show the parts of the teeth on each side of the mouth that you can see; they do not show much of the root of the tooth, which is under the gumline.

The reason bitewings are important is that they show the interproximal areas; that is, the contact points between the teeth. These are very difficult, if not impossible, to see during a visual exam, but it’s also the place where a good percentage of decay begins. If the dentist can see that decay is taking hold very early, it can be treated easily, before it turns into a toothache!

Periapical X-rays

Periapical x-rays, or PAs for short, show the entire tooth from crown to the tip of the root. These are very helpful if you have a toothache, as it will show if there is a problem in the nerve space of the tooth or at the root tip.

Many patients find these to be a bit uncomfortable. If you do, you can ask the assistant or hygienist if a smaller holder can be used. Sometimes this is not possible, however. The good thing is that today’s dental x-rays take only a fraction of a second to expose, so it will be over quickly!

Panoramic X-rays

Many patients will have a panoramic x-ray done at some point, but it’s not usually done as a matter of routine. A panoramic x-ray shows the structure of the teeth and jaws. It is also sometimes done as a substitute for a full mouth series of x-rays.

During this type of x-ray, you will sit or stand in a specific position while the x-ray machine rotates around you. You will need to remain still for up to about 20 seconds while the film is being exposed.

Full Mouth Series

A full mouth series of films is generally between 12 and 20 x-rays. They include four bitewings and eight to 16 periapicals. These are done once every several years for most patients. They are important so the dentist has a baseline to show what work you have had done, what work needs to be done, and what problems, if any, are present.

Some patients worry about the level of radiation required during dental x-rays. It is important that you only have x-rays that are needed for a specific benefit. You will be given a lead apron to wear to protect your reproductive organs and, in some cases, your thyroid.

The amount of radiation absorbed from one dental x-ray is roughly the same amount that you would absorb during the course of a regular day just walking around and performing your regular routine. So having a full mouth series will expose you to the equivalent radiation that you would be exposed to during 12 to 20 days of regular life. This is a negligible risk; you can rest assured that the tiny amount of radiation that is present when having dental x-rays almost certainly will cause you no harm.

If you have questions about any facet of your dental health care, please give our office a call!